《高能物理学会第七届全国会员代表大会暨学术年会》PPT课件

BEEIXx9Rong-GangPingIHEP, Beijingfor the BES Collaboration高能物理学会第七届全国会员代表大会暨学术年会2006年10月28－11月1日，广西.桂林

 J Deays at BESII Rong-Gang Ping IHEP, Beijing for the BES Collaboration 高能物理学会第七届全国会员代表大会暨学术年会 2006年10月28－11月1日,广西.桂林

Outline: 1 PWA on Xco →π+π-K+K-XcJ → ΦΦ,ww, PPP3.XcJ →pn-,pn4.XcJ →-三+,-,Kpp.5. summary

Data samplesMass(MeV)14LS370014M2h.12X3500P%2001.Nov.01toYY102002.Mar.0233008310064MW3Sn3M42900YYPC0~71+0,1,2++1~2P-wavecharmoniaMKICBALBESIBESILCLEOCMKIlMKIILdecays6.42 pb-1continuum data atXc0,Xc1, Xc2Ecm=3.65GeV forbkg study

0 2 4 6 8 10 12 14 MKI MKII MKIII CBAL BESI BESII CLEOc Data samples  P-wave charmonia decays c0 , c1 , c2 3M 14M 6.42 pb-1 continuum data at Ecm=3.65 GeV for bkg study. 4M 2001.Nov.01to 2002.Mar.02

1. PAW on Xco →+π-K+KMotivation :ACompared with vector and pseudoscalar mesons,little information on scalar and tensor mesons areknown. The decays of cj provide a direct window onstuding of 0++ and 2++ mesons.Differentwayforscalarstudy1. Startfrom JPC=O++,1++,2+2.Startfromgluon+gluon3.Pair production of scalars,very differentfrom J/ decays

Motivation : ▲Compared with vector and pseudoscalar mesons, little information on scalar and tensor mesons are known. ▲ The decays of cJ provide a direct window on studing of 0++ and 2++ mesons. Different way for scalar study: 1. Start from JPC=0++, 1++, 2++ 2. Start from gluon+gluon 3. Pair production of scalars, very different from J/y decays

BES:PRD72,092002 (2005)Xc0→元+元-K+K200 %cc(3414.7±0.6MeV)1. ZQ; = 0 ;1Xc (3511.3±1.3MeV)2. p(元+)+p(元-) >650 MeV(Xc2(3556.4±0.9MeV)[BG:4'→元+元-J/ 4];Eventlevel3.Prob(元+元-K+K-)>100Prob(元元一元+元一）&KProb(KKK)> Prob(KK)4. M([497±50]03.3.43.53.73.65C-fitMeV/c2&secondvertexM(元*元KK)(GeVic2)S1371events<5mm [BG: KS ];751.Avoid introducing a hugenumber of partial waves;502. constrained by presentstatistics, our study is devotedXco25to co →π+元-K+K-O3.3753.43.4253.45M元元K+K）（GeVl2

1. SQi = 0 ; 2. p( + )+p( − ) > 650 MeV [BG:’→  +  − J/ ]; 3. Prob(   +  −K+K− )> Prob(   +  −  +  − )& Prob( K K )> Prob( K K K K ); 4. M( ) [497±50] MeV/c2 & second vertex <5mm [BG: KS ]; Event level c0 →  +  − K + K − 1.Avoid introducing a huge number of partial waves; 2. constrained by present statistics; our study is devoted to c0→  +  − K + K − 1371 events c0 c1(3511.3±1.3MeV) c0(3414.7±0.6MeV) c2(3556.4±0.9MeV) 5C -fit BES: PRD72, 092002 (2005)